Auxiliary heating apparatus



Dec. 24, 1968 D. F. TYSON 3,417,920

AUXILIARY HEATING APPARATUS Filed March 6, 1967 INVENT R o DONALD E TYSON l M: ATTOIHG-Y United States Patent 3,417,920 AUXILIARY HEATING APPARATUS Donald F. Tyson, 861 Brock St., Victoria, British Columbia, Canada Filed Mar. 6, 1967, Ser. No. 621,025 2 Claims. (Cl. 237-123) ABSTRACT OF THE DISCLOSURE An apparatus for extracting heat from exhaust gases of an internal combustion engine and using such heat to supplement the heat supplied by the operating engine to a hot water heating system.

Background of the invention This invention relates to apparatus which is particularly adapted for use in providing an additional source of heat for the hot water heating systems of motor vehicles, such as a car or truck.

A number of devices have been suggested for use in extracting and using the heat of the exhaust gases of an engine but, for various reasons, these devices have never been widely accepted by car manufacturers or car owners alike. For example, some devices intended for this purpose are required to be manually operated. If not shut off at the proper time, the devices can cause serious overheating of the motor and can otherwise interfere with normal engine operation. Some devices are expensive to manufacture and difficult to install. Others require quite extensive changes to the conventional heating system which many car owners are reluctant to make. Still others fail to provide an adequate supply of heat Within moments of starting a cold motor which defeats the main purpose of installing a supplementary heater.

Summary of the disclosure The present auxiliary apparatus combines a particularly efiicieut heat exchanger with an extremely simple and fully automatic control valve. These two elements can readily be inserted into nearly all conventional hot water heating systems. Once inserted into the system and fitted to the exhaust manifold, the apparatus is capable of supplying an almost immediate supply of heat for warming the passenger compartment, defrosting Windshields and generally reducing the warm-up time of a motor.

Brief description of the drawing FIGURE 1 is a side elevation of an engine fitted with the auxiliary heating apparatus, in accordance with this invention,

FIGURE 2 is an enlarged longitudinal section of the valve included in the apparatus,

FIGURE 3 is an enlarged vertical section showing the heat exchanger of the apparatus mounted on an exhaust manifold, and

FIGURE 4 is a schematic view showing an alternative use for the auxiliary heating apparatus.

Description of the preferred embodiment Referring particularly to FIGURE 1, the numeral indicates generally an internal combustion engine of the type used in motor vehicles, such as cars and trucks. Such an engine has an exhaust manifold 12 through which the hot exhaust gases from the cylinders are conducted.

The engine or motor 10 has a water pump 14 which draws coolant from the cylinder block 15 of the motor through an outlet pipe 16. Pipe 16 is fitted with the usual thermostat 17 which remains closed until the water within the block 15 reaches a predetermined high temperature. A hose 19 connects the thermostat 17 to the top of a radia- ICC tor 20. The bottom of the radiator 20 is in communication with the engine block 15 through a hose 21.

The vehicle powered by the engine 10 has a bulkhead or fire wall 24 and mounted on this fire wall is a hot water heater 25. The heater 25 is adapted to provide warm air to the driver and passenger compartment 26 of the car. An inlet pipe 27 and an outlet pipe 28 are provided on the heater 25, these pipes projecting through the fire wall 24. The thermostat 17 and the inlet pipe 27 are connected by a hose 30. A bottom hose 31 connects the outlet pipe 28 to the engine block 15. Thus, water heated by the engine 10 can be circulated through the compartment heater 25 and back to the block 15 with the several parts providing the vehicle with a hot water heating system generally indicated by the numeral 32. As customary, the heater 25 has a manually controlled by-pass valve, not shown, which can be operated when heat is not required in the compartment 26. The heated water is then returned directly to the block 15 without passing through the heater 25. The heater 25 also supplies warm air through a duct 49 to a windshield defroster 50.

The auxiliary heating apparatus forming the subject matter of the present invention includes a thermostatic valve 40. As shown best in FIGURE 2, the valve has a two part hollow body 41 in which a cylindrical chamber 42 is formed. Aligned inlet and outlet sleeves 43 and 44 are fitted to the body 41 to communicate with the chamber 42. These inlet and outlet sleeves 43 and 44 have Y branches 45 and 46. Branch 45 provides an outlet from sleeve 43 and the branch 46 provides an inlet to the sleeve 44.

Extending across the chamber 42 of the thermostatic valve 40, is a circular fiap 54. Flap 54 is hingedly mounted on a transverse hinge pin 55. Pin 55 is slightly above the centre of the flap 54 with the result that said flap is unbalanced. A second transverse pin 57 anchors one end of a coiled thermostatic spring 58 to the body 41. The opposite end of the spring 58 is secured to an eye 59 on the flap 54. When the spring 58 is cold, it exerts a light pressure on the flap 54 to hold said flap in fluid tight sealing engagement with the inner surface of the body 41 and prevent fluid flow through the chamber 42. As the thermostatic spring 58 becomes heated, it loses tension thereby permitting the unbalanced flap 54 to swing to the dotted line position of FIGURE 2 and open the valve 40. Movement of the unbalanced flap 54 to this open position is assisted by pressure of the fluid within the sleeve 43.

Referring now to FIGURE 3, the numeral indicates generally a heat exchanger consisting of a tube 66 having a small diameter bore 67. Tube 66 has an upper or inlet end 68 and a lower or outlet end 69. Near the outlet end 69, the heat exchanger tube has a threaded portion 71. Another threaded portion 72 is provided on the tube 66 near to the inlet end 68. Between the portions 71 and 72,

the tube 66 is provided with a number of radial fins 74.

The heat exchanger 65 is adapted to be fitted to the exhaust manifold 12. Preferably this is done by drilling a small opening 78 in the lower Wall 79 of the manifold 12. A large opening 80 is formed in the upper wall 81 of the exhaust manifold. Both the openings 78 and 80 are suitably threaded. The tube 66 is inserted through the large opening 80 and is threaded into the small opening 78. A nut 83, having both internal and external threads, is secured to the portion 72 of the tube and to the large threaded opening 80. A gasket 84 is provided between the nut 83 and the upper Wall 81 of the manifold 12 to serve as a seal against the escape of exhaust gases. The tube 66 is fitted with a lock nut 86 which is threaded to the external threads of the nut 83. A second gasket 87 is provided between the lock nut 86 and the top of the nut 83.

The thermostatic valve 40 is adapted to be secured to a suitable part of the engine block 15. Conveniently, the

valve 40 can be attached to the engine by a pair of brackets 90, see particularly FIGURE 2. Alternatively, the valve 40 and exchanger 65 are constructed as a single unit. In such a case, the outlet end 68 is secured directly to the sleeve 43 so that the bore 67 is in communication with the interior of said sleeve. Suitable means, not shown, is provided to mount the apparatus on the exhaust manifold or an engine part adjacent thereto.

The thermostatic valve 40 and the heat exchanger 65 of the illustrated example of the present apparatus are connected together by hoses 93 and 94, see FIGURE 1. Hose 93 extends from the branch 45 to the inlet end 68 of the tube 66. The branch 46 and the outlet end 69 of the tube are connected by the hose 94. Hose 93 and 94 are of the same diameter which is smaller than the common diameters of the hoses 30 and 31. However, the diameter of the hoses 93 and 94 is considerably larger than the diameter of the bore 67 of the heat exchanger tube. Thus, the relatively small 'bore 67 provides a restricted passage for water flowing through the heat exchanger.

The hose 30 from the thermostat 17 to the heater 25 is cut to provide lengths 30a and 30b. The hose length 30a is connected to the inlet sleeve 43 of the thermostatic valve. Hose length 30b is connected to the outlet sleeve 44 of the valve. Thus, the auxiliary heating apparatus is fitted to the engine and is connected to hot water heating system 32. It will be noticed the apparatus provides a by-pass in the system 32. Whether the valve 40 is open or closed, fluid will flow between the hoses 30a and 30b of the system.

When the engine 10 is started cold, the thermostat 17 is closed to prevent circulation of water through the radiator 20. The pump delivers water to the hose 30a but this water is stopped from flowing directly to the heater by the valve 40 which, at this time, is also closed. Fluid flow does take place through the hose 93, heat exchanger 65, hoses 94 and b to the compartment heater 25, thence through hose 31 back to the block 15. Very shortly after the engine is started, the tube 66 becomes heated to a high temperature by the flow of exhaust gases through the manifold 12. As water is pumped through the restricted bore 67, it picks up heat from the tube 66 and delivers this heat to the compartment heater 25 and the defroster 50. Thus, a very short time after the engine 10 is started, a supply of heat is available for use in clearing a fogged or frosted windshield and for warming the occupants of the compartment 26. The preheated water being returned to the block 15 from the heater 25 adds heat to the coolant within said block, and in so doing, effects a reduction in the time required for the engine 10 to reach normal operating temperatures. As the fluid in the system 32 becomes warmer, the thermostatic spring 58 gradually becomes Weaker and the flap 54 is progressively swung about the hinge pin 55 to open the valve 40. Heated water from the block 15 can then flow directly to the compartment heater 25. A portion of this water is by-passed through the heat exchanger 65 with the result that additional heat is added thereto. This additionally heated Water increases the heat output from the heater 25 and enables said heater to supply air to the defroster 50 at a temperature which will assist in the removal of melting snow or ice from the car Windshield.

The water being returned to the block 15 at this time is also at a higher than normal temperature and this water mingles with the cooled water being delivered to the block by the radiator 20. As a result, the cooled water from the radiator is warmed slightly and the engine is able to operate at a more constant temperature which is believed to increase engine efiiciency. The Warm water injected into the block is not at a sufliciently high temperature to interfere with the proper functioning of the cooling system.

In FIGURE 4 the auxiliary heating apparatus is shown directly connected to the system 32 to supply additional heat to the block 15 rather than directly to the heater 25 as in the main embodiment of the invention. For this purpose, the hose 31 is cut to provide lengths 31a and 31b which are connected to the inlet and outlet sleeves 43 and 44 respectively. The hose 93 connects the branch 45 to the inlet end 68 of the heat exchanger 65 as before. Also, the hose 94 connection between the branch 46 and outlet end 69 of the heat exchanger is as previously described.

The present apparatus is used in this manner when it is considered more important to heat the block 15 rapidly after a cold start than it is to supply heat immediately to the compartment 26. The engine is quickly brought up to its optimum operating temperature and the heater 25 and defroster 50 subsequently benefit from this rapid warming of the motor.

Since the auxiliary heating apparatus will reduce the period required to heat a cold 'block, the engine lubricants will flow more freely sooner than would otherwise be the case and the engine is subjected to less wear. The apparatus is fully automatic so that there is no danger of overheating through failure to operate a manual control. The only tmoving part in the apparatus is the flap 54 of the valve 40 with the result that little or no maintenance is required.

I claim:

1. The combination with a hot water heating system and an engine exhaust manifold for a vehicle, of an auxiliary heating apparatus comprising a thermostatic valve having a hollow body, an inlet and an outlet communicating with said hollow body, said inlet and said outlet being connected into the hot water heating system and each having a branch, a heat exchanger fitted to the exhaust manifold to extract heat from gases flowing therethrough and having an inlet and an outlet, means connecting the inlet branch of the thermostatic valve to the heat exchanger inlet, means connecting the outlet branch of the thermostatic valve to the heat exchanger outlet, said heat exchanger including a tube having a restricted bore, said restricted bore limiting the water flow through the heat exchanger to a predetermined small volume when the thermostatic valve is either open or closed.

2. The combination as claimed in claim 1, in which said thermostatic valve comprises a flap mounted on a hinge pin extending across the hollow 'body for swinging movement between a valve open and a valve closed position, said hinge pin being slightly off-centre with respect to the flap whereby said flap is urged to open position by water pressure within the inlet side of the hollow body.

References Cited UNITED STATES PATENTS 1,528,788 3/1925 Rayfield 123-411 X 1,558,009 10/1925 Giesler 123-41.1 1,873,591 8/1932 James 123-4l.1 2,023,920 12/1935 Eisinger et al. -35 2,080,600 5/1937 Bremer 123-41.09 1,990,159 2/ 1935 Angstman 237-123 2,749,050 6/1956 Booth 237-123 1,833,067 11/1931 Caesar 237-123 1,269,753 6/1918 Shum 165-52 2,077,764 4/1937 Liles 165-35 2,258,324 10/1941 Hans 165-51 2,282,087 5/1942 Pena 165-51 X 3,131,757 5/1964 Bergstrom et al. -3" 165-51 X 3,223,150 12/1965 Tramontini 165-34 ROBERT A. OLEARY, Primary Examiner. ALBERT W. DAVIS, JR., Assistant Examiner.

US. Cl. X.R. 237-34; 165-35, 40, 51 

